A better alternative to subdomains

Hey, been getting into autoblogs lately and I'm wondering if anyone has had experience with running multiple blogs on one domain. There are basically two ways to do this from what I can tell. Create a subdomain for each niche/subniche you want to target, or create a wordress install in a new diectory of the main domain (ex http://somedomain.com/blog2 .. /blog3 .. etc).

Obviously investing in a new domain is best, but what I'm wondering is if creating a new blog on the top level domain is better because google see's this as just an extension of the original site and therefore will give it more weight.

What I like about Wordpress Mu is you don't have to install plugins on every new blog. Once installed on top blog you can make them available to all sub blogs, then just activate them on new blog. I can be tricky to install, I always have to mess around with it to get it to work.

Note that adblockers might block our captcha, and other functionality on BHW so if you don't see the captcha or see reduced functionality please disable adblockers to ensure full functionality, note we only allow relevant management verified ads on BHW.